Traffic Data Acquisition is among one important tasks in ITS. All the on-line or historical data are vital for the design and planning for the traffic management strategy. The traffic data acquisition device normal consists of two parts: the sensor and the controller. The controller links with the central through wire-line connection and send back the data collected from the sensor. However, installation of the wire-line relates to huge engineering efforts and the maintenance of fixed lines has always been difficult. There will be more problems to get wire-line connection in remote areas. When the communication line goes down, data is lost unless a data Logger is further installed.

In this application, wireless module links with the Traffic Data Acquisition device using RS485 interface. The raw data from the detector is further analyzed by the data protocol analysis mechanism provided by the wireless module and sorted data is transmitted to the central Traffic Control Centre through GPRS network and Internet in TCP/IP packet. Data can be temporarily stored in the memory buffer when GPRS is disconnected. From the system integrator"s point of view, all the integration on the terminal wireless connection is achieved by the plug & play of wireless module and no change is necessary on the original detecting device. And only simple application is required at the central to access the terminal data. The total system implementation is accomplished within 3 weeks.